Contact bar assembly for a warp stop motion of a loom

ABSTRACT

A contact bar assembly for the warp stop motion of a loom includes an inner bar (1) having a beam-shaped part (2) of insulating material at the upper edge of which a groove (5) is provided for the reception of a metallic serrated bar (6), and the entire inner bar can longitudinally reciprocate in an outer bar (8) of a U-shaped cross section. The outer bar (8) has longitudinally spaced slots (12) each for the reception of a guide piece (12) of synthetic material which can easily be inserted and removed, each guide piece having a longitudinal slot (13) with a larger configuration (14) at its lower section. The beam-shaped part (2) of synthetic material has a lower section of T-shaped cross-section (4) and (10) which engages with slot (13) and its larger configuration (14) for holding and guiding the inner bar (1) in such a manner that a vertical separation of the inner bar from the outer bar is prevented, although the inner bar is capable of longitudinal reciprocation in the outer bar (8). The longitudinal edge of the inner bar located beyond the free ends of the legs of the U shaped outer bar has about the same thickness as the outer bar and covers a slot (9) of the outer bar (8) to prevent entry of fluff and dust.

The invention relates to a contact bar assembly for the warp stop motionof a loom and comprises a metallic outer bar of U-shaped cross sectionand an inner bar housed partly within the outer bar, electricallyinsulated, which can be longitudinally reciprocated in the outer bar andwhich is serrated across the width of the top edge.

With a known contact bar assembly of such type (Swiss Pat. No. 430611),the inner bar is housed deeply within the legs of the outer bar ofU-shaped cross section and is separated by insulating plates from theselegs of the outer bar, whereby the total width of the contact barassembly becomes very thick and the associated drop wires will have toinclude a correspoonding wide contact slot. This known assembly does notpermit a complete removal of the inner bar from the outer bar forcleaning or repair purposes, since a bolt extends transversely throughthe legs of the outer bar and through a slot of the inner bar, resultingthat reciprocation of the inner bar is limited and can only perform in amanner which corresponds with the length of the slot. The cross boltwhich is firmly arranged in the outer bar prevents a complete removal ofthe inner bar from the outer bar.

In order to render the cross section of the contact bar assemblynarrower, it is futhermore known (DE-OS No. 2340714) to make the innerbar only of insulation material having a narrow cross section fitting inbetween the two legs of the outer bar and which has one longitudinaledge located beyond the free ends of the legs from the bight of the Uonto which a conductive and serrated bar is mounted in order to providesufficient vertical space between the outer bar and the metallicconductive part to ensure adequate insulation, so that moist fluff anddust sticking on the surface of the outer and inner bars may not lead toshort circuit and subsequent faulty stoppages of the loom.

With this known contact bar assembly, the inner bar is not guided andmaintained in such a manner that a longitudinal reciprocation and acomplete removal of the inner bar from the outer bar for cleaning orrepair purposes is possible, and a separation of the inner bar from theouter bar in a vertical direction from the slot or bight of the outerbar is not possible.

The principal object of the present invention is to provide a contactbar assembly, the two bars of which-without major expenditure inmanufacture concerning the shape of the outer bar and the innerbar-being coupled and guided for longitudinal reciprocation movementsuch, that the inner bar can be easily and completely removed from theouter bar, and that, however, during operation the inner bar cannot betaken out in vertical direction from the bight or slot of the U of theouter bar. Such longitudinal guidance while at the same time preventinga disengagement in vertical direction should be accomplished by simplemeans and, moreover, it should, by simple means, prevent dirt or flufffrom entering between the bight of the U of the outer bar and thesurfaces of the inner bar. The contact bar assembly according to theinvention carries out this broad objective and has the advantages thatthe necessary parts needed for the longitudinal guidance and couplingarrangement of the inner bar to the outer bar is reasonable in price andeasy to assemble. The openings made at intervals in the outer bar willappropriately be configured as slots extending transversely through theouter bar, whereby an appropriate guide piece preferably made ofsynthetic material having the shape of the slot fits exactly into thesame. The guide piece is preferably held by means of snap fastening inthe outer bar, and for this reason, the guide piece is appropriatelyconfigured with a protrusion at the centre of its lower edge, and abovethe same, is configured with a slot which makes it possible that theprotrusion can resiliently snap into the slot of the outer bar ofU-shaped cross section.

Further details and advantages will be understood from the followingdescription in which an embodiment is explained with reference to theaccompanying drawing of which:

FIG. 1 is a view of the inner bar in side-elevation

FIG. 2 is an end view of the inner bar according to FIG. 1

FIG. 3 is a side view of the contact bar assembly consisting of outerbar and inner bar with two guide pieces fitted in the outer bar at aninterval

FIG. 4 is a sectional view taken through the outer bar only along lineI--I FIG. 3 in an enlarged scale

FIG. 5 is a sectional view taken through the outer bar and inner baralong line I--I of FIG. 3

FIG. 6 is a sectional view taken through the inner bar only along lineI--I of FIG. 3

FIG. 7 is a view in side-elevation of the guide piece in a larger scalethan shown in FIG. 3

FIG. 8 is a sectional view taken through the guide piece line II--II ofFIG. 7.

The inner bar 1 according to FIG. 1 consists of a beam-shaped part 2 ofinsulating material and having a T-shaped section 4, 10 at the lowersection of part 2, the cross section of which part 2 is illustrated inFIG. 2 and in an enlarged scale in FIG. 6. Its upper section 3 isconfigured broader than its lower section 4 and the broader sectiondiminishes roof-like towards the upper longitudinal edge, where a groove5 extends into part 2 of insulating material. A metallic and conductivebar 6 provided with a uniform serration 7 on its upper edge is firmlyembedded into the groove 5.

As shown in FIG. 5, the width of the roof-shaped section 3 of the part 2of the inner bar 1 corresponds at its base with the outside width orthickness of the outer bar 8 of U-shaped cross section into which theinner bar is partly housed, whereby the roof-shaped section 3 of theinner bar covers the outer bar 8 on its upper longitudinal edgesresulting that the slot 9 of the outer bar 8 is also covered andsubsequently no dust, fluff or dirt can enter.

Part 2 of the inner bar 1 has at its lower edge a longitudinallyT-shaped configured border part 10. The inner bar 1 is kept in the outerbar 8 by means of a number of guide pieces 11, fitted at longitudinalintervals from eachother into the outer bar 8, as shown in FIG. 3,whereby the longitudinal border part 10 of the inner bar engages intothe guide pieces 11, effecting that the inner bar 1 cannot be raisedfrom the slot 9 of the outer bar 8, that it however can reciprocatelongitudinally in its full length in the outer bar 8.

The guide pieces 11 are fitted in the openings which are configuredpreferably as slots 12 which extend transversely through the outer bar 8as can be seen in FIG. 4 in the enlarged scale.

In FIGS. 7 and 8 the guide piece 11 is illustrated in enlarged scale.The guide piece 11 is preferably made of synthetic material and isprovided at the upper edge with a longitudinally extending slot 13, thebottom of which forms an enlarged recess 14. Part 2 of the inner bar 1fits with its section 4 into the slot 13 and the lower larger borderpart 10 of the inner bar fits into the enlarged recess 14 appropriatelyconfigured at the base of the slot 13. With this arrangement, alongitudinal reciprocation of the inner bar 1 in relation to the outerbar 8 is accomplished, as clearly illustrated in FIG. 8. The guide piece11 fills the slot 12 completely and has the same thickness as the one ofthe outer bar 8.

The guide piece 11 is secured in the outer bar 8 by means of a snapfastening device in order to fit and remove it in a simple and easymanner. For this purpose, the guide piece 11 is configured at the centreof the lower edge with a protrusion 15 which has about the samethickness as the opening of slot 9 in the outer bar 8. Above theprotrusion 15 of the guide piece 11, there is a slot 16 extendingtranversely through the guide piece 11 giving a springy or resilienteffect of the lower section of the guide piece 11 with the protrusion 15which enables the insertion and subsequently the snapping in of theguide piece 11 with its protrusion 15 into the slot 9 in the outer bar 8when the guide piece is secured in the opening 12. The guide piece 11couples therefore the inner bar 1 firmly with the outer bar 8 preventinga removal of the inner bar 1 in vertical direction from the outer bar 8,however permitting a longitudinal reciprocation of the inner bar withoutany limitation in the outer bar.

What is claimed is:
 1. A contact bar assembly for the warp stop motionof a loom, comprising a metallic electrically conductive outer bar of aU-shaped cross-section and an electrically insulated inner bar housedpartly and guided in said outer bar, said inner bar having an upperlongitudinal serrated edge, said outer bar having longitudinally spacedopenings extending transversely therethrough, a guide piece beingreceived with each of said openings, each said guide piece having a slotextending longitudinally of the axis of said outer bar, a lower sectionof said slot having an enlarged configuration, said inner bar being ofinsulating material and having a beam-shaped part extendingsubstantially along the entire length of the bar assembly, said parthaving a lower section of T-shaped cross-section which corresponds tothat of said slot and said enlarged configuration thereof, said T-shapedlower section of said part being received within said slot and saidenlarged configuration for longitudinal guiding movement therealong andfor thereby preventing said inner bar from being removed in a verticaldirection from said outer bar.
 2. The contact bar assembly according toclaim 1, wherein each of said openings in said outer bar and each saidguide piece is of the same size and shape.
 3. The contact bar assemblyaccording to claim 1, wherein each said guide piece is of non-metallicmaterial.
 4. The contact bar assembly according to claim 1, wherein saidouter bar has a slot at each of said openings, each said guide piecehaving a protrusion at its lower edge engaged in said slot, each saidguide piece also having a through slot located above said protrusion forspring retaining each said guide piece within each of said openings insaid outer bar.
 5. The contact bar assembly according to claim 4,wherein said beam-shaped part has an outwardly open longitudinal slot atthe upper longitudinal edge thereof, a metallic bar having said serratededge being snugly received within said longitudinal slot, saidbeam-shaped part having a roof-shaped section extending from saidlongitudinal slot and overlying the length of said outer bar, saidroof-shaped section having a width equal to the thickness of said outerbar so as to prevent the entry of fluff and dust into said slot at eachof said openings.